The present invention relates to a process for the preparation of LiBF4.
LiBF4 has very useful applications in high voltage lithium primary/secondary cells. LiBF4 is well known as a battery electrolyte. This compound was earlier prepared by procedures, which were cumbersome and the yield was poor. The purity of the sample prepared was poor and needed recrystallization.
U.S. Pat. No. 5,079,109 discloses the use of LiBF4 as a non-aqueous electrolyte for a lithium battery.
While several methods are known for the preparation of LiBF4 in the prior art such methods suffer from the following disadvantages:
1. The purity of the product is low
2. The yield of the product is low
3. Ambient temperature reaction for the product yield
4. Side reactions occur
5. Multiplicity of steps are required.
The main object of this invention is to prepare LiBF4 by a simple chemical reaction.
Another object of the invention is to obtain LiBF4 with high yield.
A further object of the invention is to obtain LiBF4 by an efficient process.
The process of the invention overcomes the disadvantages of the prior art enumerated above.
Accordingly the present invention relates to a process for the preparation of LiBF4 reacting LiBO2 compound with 10 to 48% HF solution in aqueous solution at ambient temperature, concentrating the product and recrystallising to obtain high purity LiBF4.
In one embodiment of the invention, LiBO2 is suspended in aqueous media/nonaqueous media and reacted with HF.
In a further embodiment of the invention, a paste of LiBO2 is added in HF.
In another embodiment of the invention, LiBO2 is pasted with water and reacted with HF.